Optical & Mechanical I/F between SAFARI and IOB

Rev. A Mar. 12th 2010Hideo Matsuhara

Background Stringent stiffness requirement of FPIA

150Hz (Z) / 100Hz (X, Y) !! The original concept of IOB plate (ribbed Aluminum plate) itself does

not satisfy the requirement. To overcome the above problem, two options:

[Option A] IOB made of SiC (or CFRP) [Option B] MIRACLE (& MIRMES, MIRHES) base plate will be a part

of the IOB structure (made of Aluminum) On the other hand, we decide to consider a common pick-off

module (PoM) separated from each FPI, but mechanically I/F to IOB PoM is a sub-system of IOBA No moving parts

On 13th Jan, we proposed that each FPI’s envelope does NOT exist within 180f circle in the focal plane.

Concept of common PoM

Pick-off location is 100-150mm below the surface of IOB, so the PoM looks like a cylinder?

IOB may not be a plate, but a frame structure – so the PoM structural design depends on the IOB structure

f 2300 mm

[Option B] “IOB – MIRACLE-base plate common structure” concept

Note: structures of MIRACLE, MIRMES, MIRHES & FPC, SCI in these figures are now out-of-date

This option is investigated by Takehiko Wada & the MIRACLE team on behalf of the FPIA manager

Progress in the opt-mechanical design of MIRACLE, MIRMES, MIRHES, SCI and FPC

MIRACLE, MIRMES, MIRHES 1st version of optical design completed and estimated total mass &

volume Now 2nd version of optics is under investigation , aiming more compact

design - pick-off location can be slightly apart from the telescope center MIRMES pick-off is located at the re-image of the fore-optics of

MIRACLE-long MIRHES pick-off is located at the re-image of the fore-optics of

MIRACLE-short SCI

Now, no-pickoff mirror compact optical design in the housing oriented vertical

FPC Now 5x5 arcmin2 FoV FPC-G optics is under revision, FPC-S is already fixed

New SCI design

Field-of-Views (updated 11 Mar. 2010)

Issues for SAFARI – interference with FPC-S

SCI

FPC-S

Current optical rays at pick-off

SAFARI

175mm f

Note: MIRACLE optics / pick-off will be updated soon

Discussion – short-term A/Is Can [Option-B] fit the SAFARI mechanical I/F design?

can SAFARI rotate 90 deg around X-axis?

Optical I/F for SAFARI will be defined with respect to the common PoM, as we proposed before?